Search: 274b Vs 5u4g. 3극관 2개의 전극(필라멘트와 플레이트)사이에 그리드(grid) 전극을 추가한 진공관 5Z3 vs 5U4G rectifier question Now I did understand the amount of tube sockets, the layout was dedicated to a classic design with a half 6SN7 as driver stage, another 6SN7 as phase splitter and two power tubes, all served by a doubled rectifier stage with two 5U4G.
integral 22 suppressor